Microencapsulated phase change material via Pickering emulsion stabilized by graphene oxide for photothermal conversion

In this study, Pickering suspension polymerization was used to synthesize thermally stable microencapsulated phase change materials (microPCMs) with n-eicosane as the PCM, polyurea (PUA) as the shell, and graphene oxide (GO) as the colloidal stabilizer. Accordingly, the GO-modified microPCMs (GO@PUAmPCM) prepared at different GO emulsion concentrations were investigated and compared. These microcapsules exhibited high thermal storage of about 70% (180 J/g), leakage prevention, and high solar harvesting capacity with efficient photothermal conversion efficiency (60%). GO@PUAmPCM also showed good thermal reliability, and no leakage was observed after 100 heating and cooling cycles. The process developed herein can be embraced to fabricate highly efficient and reliable PCM microcapsules for solar energy harvesting.